Hermetically sealed electromagnetic relays are used for switching of high electrical currents and/or high voltages, and typically have fixed and movable contacts, and an actuating mechanism supported within a hermetically sealed chamber. To suppress arc formation, and to provide long operating life, air is removed from the sealed chamber by conventional high-vacuum equipment and techniques. In one style of relay, the chamber is then sealed so the fixed and movable contacts contact in a high-vacuum environment. In another common style, the evacuated chamber is backfilled (and usually pressurized) with an insulating gas (e.g., sulphur hexafluoride, nitrogen, or gas mixes) with good arc-suppressing properties. These gases provide dielectric and arc suppression properties in addition to protecting the contacts from oxidation.
For purposes of this disclosure, a hermetic seal means a seal which is sufficiently strong and impermeable to maintain for a long term a high vacuum of 10−5 Torr (760 Torr=one atmosphere) or less, and a pressure of at least 1.5 atmospheres.
In one embodiment described below, a relay is provided including a hermetically sealed housing, a first circuit, a second circuit, and an actuator. The first circuit includes first and second fixed contacts and a first movable contact. The first movable contact and at least part of the first and second fixed contacts are sealed within the housing. The second circuit includes third and fourth fixed contacts and a second moveable contact. The second movable contact and at least part of the third and fourth fixed contacts are sealed within the housing. The second circuit is electrically isolated from the first circuit. The actuator is sealed within the housing. The actuator has a first position in which the moveable contact is electrically isolated from the first and second fixed contacts and the second moveable contact is electrically isolated from the third and fourth fixed contacts. The actuator has a second position in which the first moveable contact is electrically coupled to the first and second fixed contacts and the second moveable contact is electrically coupled to the third and fourth fixed contacts.
According to another embodiment of the present disclosure a relay is provided. The relay includes a first fixed contact; a first moveable contact, and at least one magnet. The first moveable contact is positionable in a first area proximate the first fixed contact and a second area away from the first fixed contact. The at least one magnet applies a flux to the first area. The flux achieves a first efficacy for arc blow out for a first polarity. The flux achieves a second efficacy for arc blowout for a second polarity. The first efficacy is substantially equal to the second efficacy and the first polarity is opposite of the second polarity.
According to yet another embodiment of the present disclosure, a relay is provided. The relay comprises a first moveable contact; a second moveable contact; a housing, the housing hermetically sealing the first and second moveable contacts therein; and a carrier containing the first and second moveable contacts, the carrier providing electrical isolation between the first and second moveable contacts, the carrier being moveable within and hermetically sealed within the housing.